Fix optional Array params default to Hash

.rubocop_todo.yml

@@ -1,5 +1,5 @@
 # This configuration was generated by `rubocop --auto-gen-config`
-# on 2014-12-16 11:52:50 -0500 using RuboCop version 0.28.0.
+# on 2014-12-16 11:52:50 -0500 using RuboCop version 0.29.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -30,7 +30,7 @@ Metrics/ClassLength:
 
 # Offense count: 15
 Metrics/CyclomaticComplexity:
-  Max: 19
+  Max: 20
 
 # Offense count: 545
 # Configuration parameters: AllowURI, URISchemes.
@@ -44,7 +44,7 @@ Metrics/MethodLength:
 
 # Offense count: 13
 Metrics/PerceivedComplexity:
-  Max: 21
+  Max: 22
 
 # Offense count: 26
 # Cop supports --auto-correct.

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 #### Fixes
 
+* [#994](https://github.com/intridea/grape/pull/994): Fixed optional Array params default to Hash - [@u2](https://github.com/u2).
 * [#988](https://github.com/intridea/grape/pull/988): Fixed duplicate identical endpoints - [@u2](https://github.com/u2).
 * [#936](https://github.com/intridea/grape/pull/936): Fixed default params processing for optional groups - [@dm1try](https://github.com/dm1try).
 * [#942](https://github.com/intridea/grape/pull/942): Fixed forced presence for optional params when based on a reused entity that was also required in another context - [@croeck](https://github.com/croeck).

gemfiles/rails_3.gemfile

@@ -5,7 +5,7 @@ source 'https://rubygems.org'
 gem 'rails', '3.2.19'
 
 group :development, :test do
-  gem 'rubocop', '~> 0.28.0'
+  gem 'rubocop', '~> 0.29.1'
   gem 'guard'
   gem 'guard-rspec'
   gem 'guard-rubocop'

gemfiles/rails_4.gemfile

@@ -5,7 +5,7 @@ source 'https://rubygems.org'
 gem 'rails', '4.1.6'
 
 group :development, :test do
-  gem 'rubocop', '~> 0.28.0'
+  gem 'rubocop', '~> 0.29.1'
   gem 'guard'
   gem 'guard-rspec'
   gem 'guard-rubocop'

lib/grape/dsl/inside_route.rb

@@ -43,7 +43,8 @@ def declared(params, options = {}, declared_params = nil)
 
               if params.key?(parent) || options[:include_missing]
                 hash[output_key] = if children
-                                     declared(params[parent] || {}, options, Array(children))
+                                     children_params = params[parent] || (children.is_a?(Array) ? [] : {})
+                                     declared(children_params, options, Array(children))
                                    else
                                      params[parent]
                                    end

spec/grape/endpoint_spec.rb

@@ -295,6 +295,44 @@ def app
       expect(inner_params[:nested].size).to eq 2
     end
 
+    it 'builds nested params' do
+      inner_params = nil
+      subject.get '/declared' do
+        inner_params = declared(params)
+        ''
+      end
+
+      get '/declared?first=present&nested[fourth]=1'
+      expect(last_response.status).to eq(200)
+      expect(inner_params[:nested].keys.size).to eq 1
+    end
+
+    context 'sets nested array when the param is missing' do
+      it 'to be array when include_missing is true' do
+        inner_params = nil
+        subject.get '/declared' do
+          inner_params = declared(params, include_missing: true)
+          ''
+        end
+
+        get '/declared?first=present'
+        expect(last_response.status).to eq(200)
+        expect(inner_params[:nested]).to be_a(Array)
+      end
+
+      it 'to be nil when include_missing is false' do
+        inner_params = nil
+        subject.get '/declared' do
+          inner_params = declared(params, include_missing: false)
+          ''
+        end
+
+        get '/declared?first=present'
+        expect(last_response.status).to eq(200)
+        expect(inner_params[:nested]).to be_nil
+      end
+    end
+
     it 'filters out any additional params that are given' do
       inner_params = nil
       subject.get '/declared' do